The invention relates to a connecting device for fluid-conveying systems, in particular, for the connection of a hose, as well as to a connecting method.
Fluid-conveying systems frequently use hoses having ends that are connected to other line or devices. These hose connections are subject to considerable mechanical stresses which must not compromise the seal between the hose and the nipple or any added lines. Frequently, connecting means are used that are based on the plastic deformation of a sleeve extending over the hose. To achieve this, for example, document DE 38 08 383 A1 discloses a nipple and a hose-receiving section that has a conical, cylindrical or other profile and ribs, as well as a compression sleeve that at least extends over said ribs to achieve axial securing, and that clamps the hose in place on the hose-receiving section of the nipple, when said hose-receiving section is deformed, i.e., compressed, in axially inward direction.
Such a compression sleeve has also been known, for example, from document DE 101 04 448.
The connection of a nipple with a hose by means of a compression sleeve has also been known from document EP 0 057 920 A1. Again, the nipple has a cylindrical hose-receiving section and a rib that is provided adjoining said hose-receiving section. The compression sleeve extends over the rib, thus securing said sleeve on the nipple in axial direction. The compression sleeve has several peripherally extending ribs on its inside peripheral surface. When the hose is slipped onto the nipple, said compression sleeve is compressed in radially inward direction, so that its ribs are pressed into the hose and thus tightly secure said house in axial direction and in a fluid-tight manner on the nipple.
Such compression connections have been widely accepted. However, they can cause problems when the hose and the nipple are stressed relative to each other due to a torsional moment. Such torsional moments can occur due to movements of the components connected to each other by the hose, or even by vibrations, temperature changes during assembly, or as a result of assembly. It must be ensured that such torsional moments do not compromise the connection between the hose and the nipple. This problem is becomes more pronounced as the fluid pressures to be endured by the hose become greater. Increasing pressure requires an increasingly stiffer hose wall. A particularly stiff hose already generates a significant counter-torque when its ends are only slightly rotated relative to each other, this counter-torque stressing the connection site between the nipple and the hose. In the course of time, such stresses can cause the nipple to loosen or to impair its seal.
Considering this, it is the object of the invention to create a connection device for fluid-conveying systems which is insensitive to relative torsional moments. In addition, a corresponding method of connection is to be provided.